It is known to provide gunfire simulators which simulate the flash and noise of a gun being fired or the strike of an explosive projectile. At their simplest such gunfire simulators may be no more than blank cartridges which directly take the place of live ammunition. However for use in simulating the firing of battlefield weapons from small arms through missile launchers to heavy guns such as tank guns and field artillery it is known to provide pyrotechnic devices which are housed in a metal block which may, for example, hold 12,20 or 24 rounds and which is fixed to the exterior of the weapon platform close to the barrel of the weapon in question. Usually the weight of such devices is such that they cannot be fixed directly to the barrel of the weapon. Often the devices are sufficiently bulky to create an obstruction to the sight of the tank or gun crew. Since such devices are limited to a relatively small number of rounds, a lack of realism can result. Also the cost of the pyrotechnic devices, while being much less than that of live ammunition, is nevertheless appreciable.
Our U.K. patent GB-B-2250333 discloses a gunfire simulator intended to address these problems and comprising a combustion chamber, means for admitting fuel gas to the combustion chamber, a flap valve for admitting air to the combustion chamber, means to force ambient air into the combustion chamber through the flap valve, ignition means for igniting fuel gas in the combustion chamber to cause an explosion, an exhaust port in the combustion chamber and outlet valve means for closing the exhaust port and arranged to open rapidly and with audible results in response to explosive pressure rise within the combustion chamber. Outlet valve means comprising a frangible diaphragm is specifically disclosed.
In the gunfire simulator disclosed in U.K. patent GB-B-2250333, the diaphragm may be part of a web, tape or ribbon of the thin sheet extending across the exhaust port and which is movable to position a fresh section of the sheet to close the exhaust port between one explosion and the next, and the simulator comprises means for feeding a fresh section of the web to the exhaust port after each explosion, and an automatic breechblock mechanism for releasably clamping a fresh section of the sheet in position during each explosion.
It is an object of the invention to provide a novel gunfire simulator of the same general kind as is disclosed in our U.K. patent GB-B-2250333.